Abstract : Less fiber consumption will cause constipation. Dietary fiber has the ability to bind water in the colon to make the volume of feces bigger and will stimulate the nerves in the rectum The aim of the study was to determine the effect of pie product from fermented black glutinous rice and sweet purple potato to frequency of defecation in adolescent with constipation. The experimental research design used two groups pre and posttest with control experimental design. The population in this study were adolescents who lived around the Poltekkes Bandung. The number of samples is 19 people in each group. The study was conducted for 14 days. The intervention group was given 2 pieces of pie product from fermented black glutinous rice and sweet purple potato and a high-fiber diet education. The control group was educated on a high-fiber diet. Statictical analysis used was Wilcoxon and Mann Whitney test. Statistical tests with Wilcoxon showed a significant difference in the frequency of defecation at the beginning and end of the study with a value of p <0.001 (p≤0.05). The Mann-Whitney test showed that there was an effect of pie product from fermented black glutinous rice and sweet purple potato to the increased frequency of defecation in adolescents suffering from constipation with a value of p <0.001 (p≤0.05). It is necessary to socialize the importance of consuming fermented black glutinous rice as an alternative snack to prevent constipation